使用标签和PerformSegueWithIdentifier通过tabBar DidSelectItem传递数据

Question

I am using swift 3 have a taBbar and when I select an tabBarItem the segue is called programatically to go to a new View Controller. I also need to pass some data with this segue.

my code (for tabbar didSelectItem):

 func tabBar(tabBar: UITabBar, didSelectItem item: UITabBarItem) {
        if item.tag == 0 {
            self.performSegueWithIdentifier("nearbyHotelsSegue", sender: nil)
        } else if item.tag == 1 {
            self.performSegueWithIdentifier( "nearbyRestaurantsSegue", sender: nil)
        } else if item.tag == 2 {
            self.performSegueWithIdentifier( "nearbyEventsSegue", sender: nil)
        } else if item.tag == 3 {
            self.performSegueWithIdentifier( "morePlacesSegue", sender: nil)
        } 
    }

From my research so far, I know that can use PrepareForSegue for this, but I can't use this inside the tabBar (didSelectItem) method. How can I pass data using tabbar didSelectitem method or is there any other good way to achieve this? Thanks.

Answer 1

The prepareForSegue method is used as an overridden one, so you should use it out of tabBar function's bounds. When you call performSegue(withIdentifier: "segueName", sender: nil) , you have given nil in sender. Sender is the parameter of type Any? , where you put your custom data you want to pass to another controller. In prepare(forSegue: UIStoryboardSegue, sender: Any?) when you cast your destination view controller as the one you want to use, pass the sender data to this controller, eg:

override func prepare(forSegue: UIStoryboardSegue, sender: Any?) {
if let controller = segue.destination as? YourDestinationViewController {
controller.receivedData = sender
}
}

Answer 2

I solved this using the following code. it seems prepareForSegue is not effected by the use of PerformSegueWithIdentifier to perform the segue programmatically.
So I used the code posted in the question unchanged and then added the following code to pass data.

 override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "nearbyHotelsSegue" {

            if let toViewController = segue.destinationViewController as? NearbyHotelsViewController {
                toViewController.returnedText = (searchBaseItem?.baseItemId)!
            }
        }

//....other ifs
}